How the SIP maturity value is calculated
A SIP is a series of equal monthly investments, and each instalment compounds for a different length of time. The tool uses the standard future-value-of-an-annuity-due formula:
FV = P × [((1 + r)^n − 1) / r] × (1 + r)Where:
- P = your monthly investment
- r = monthly rate = annual return ÷ 12 ÷ 100
- n = total months = years × 12
The trailing (1 + r) assumes each instalment is invested at the start of the month, so it earns one extra month of growth. When the expected return is 0%, the formula collapses to simple accumulation (FV = P × n) — the tool handles that edge case explicitly so you never divide by zero.
The two headline numbers come straight out of this: amount invested is just P × n, and wealth gained is the maturity value minus what you put in. The growth multiplier shown alongside the corpus is total ÷ invested.
Why the multiplier matters more than the rate
People fixate on the return percentage, but the real lever is time. Investing ₹5,000 a month at 12% turns ₹12 lakh of contributions into roughly ₹49.9 lakh over 20 years — you put in ₹12 lakh and the market adds nearly ₹38 lakh on top. Stretch the same SIP to 25 years and the corpus jumps past ₹94 lakh, because the final years are compounding on the largest base. That is why starting early beats investing more: a head start is the one variable you can never buy back later.
A few honest caveats the calculator can’t model: the 12–15% figure quoted for Indian large-cap equity funds is a long-run historical average, not a guarantee — actual returns are lumpy and some years are negative. The corpus shown is also pre-tax; equity long-term capital gains above ₹1 lakh are taxed at 10%. Use the result as a planning estimate, not a promise.
Privacy
Every projection runs in your browser via the pure calculateSIP function. Changing the amount, rate, or duration triggers zero network requests — you can confirm this in your browser’s Network tab. Nothing about your investment plan is stored in localStorage, sent to analytics, or transmitted anywhere.
Related calculators
Pair this with the lumpsum calculator to compare one-time versus monthly investing, the compound interest calculator to understand the engine underneath, or the retirement calculator to back out the monthly SIP a target corpus needs.